Now, correct me if I'm wrong, but isn't the whole browser fingerprinting "thing" (for lack of a better word) a bit more complex than that?
If I recall, a browsers fingerprint doesn't just list your addons, cookies, hardware information, etc. simply in plain like this:
Addons: uBlock, NoScript, FoxyProxy
Hardware: 1920x1080, I5@2,5ghz
Cookies: amazon, google, youtube, etc.
But rather uses all the data to create a value based on them which is unique to you allowing tracking and fingerprinting. And, as far as I'm informed, such a value is freshly created when installing FoxyProxy. So, even if many TBB users use FoxyProxy with it, that doesn't mean they are just a part of a smaller group. By design, they'd be unique then.
Hasn't that been the reason why, despite many developers having tried to do so, there has been no way to protect from fingerprinting and tracking without giving many people a predifined and identical value like the TBB does? Like I've said, if this is fundamentally wrong I'm sorry, but that is what I've been reading time and time again.
Have a nice day,